NUMERICAL SIMULATION OF VORTEX SHEDDING PAST A CIRCULAR CYLINDER IN A CROSS-FLOW AT LOW REYNOLDS NUMBER WITH FINITE VOLUME TECHNIQUE. - PART 2: FLOW-INDUCED VIBRATIONS

摘要

This paper is the sequel of the work exposed in a companion publication dealing with forced oscillations of a circular cylinder in a cross-flow. In the present study, oscillations of the cylinder are now directly induced by the vortex shedding process in the wake and therefore, the former model used for forced oscillations has been modified to take into account the effects of the flow in order to predict the displacement of the cylinder. The time integration of the cylinder motion is performed with an explicit staggered algorithm whose numerical damping is low. In the first part of the paper, the performances of the coupling procedure are evaluated in the case of a cylinder oscillating in a confined configuration for a viscous flow. Amplitude and frequency responses of the cylinder in a cross-flow are then investigated for different reduced velocities U* ranging from 3 to about 15. The results show a very good agreement at Re=100 and the vortex shedding modes have also been related to the frequency response observed. Finally, some perspectives for further simulations in the turbulent regime (at Re=1000) with structural damping are presented.